Excavator



May 12, 1931. R. M. BOWMAN ET AL 1,804,587

' ExcAvAToR. 'r

' Filed Dec. 28, 1926 3 Sheets-Sheet l f INVENToR.

RUDOLPH M. Bow/WAN BRUCE L. BOWMAN- A ATTORNEY. i

My 12, 1931. R. M. BowMAN ET 1Mf 1,804,587

EXCAVATDR Filed Dec. 28, 1926 3 Sheets--Shee'kI 2 INVENTOR. Y `RUDOLPH M. BOWMAN BRUCE L. BOWMAN ATTORNEY.`

l May l2, 1931.

R. M. BOWMAN ET AL EXCAVATOR Filed Deo. 5 Sheets-Sheet 3 1 INVENTOR. RUDOLPH M. BOWMHN BRUCE L. BOW/WAN ATTORNEY.

Patented May 12, 1931 PATENT OFFICE RUDOLPH M.`BOWMAN AND BRUCE L. BOWMAN, OF HOLLYWOOD, CALIFORNIA ExcAvAToa Application filed December 1926. Serial No. 157,476.

This invention relates to excavators. The general object of the invention -is to provide 'a novel excavating machine which is particularly adapted for moving said machine to reduce grades.

Aspecitic object of the invention is to provide an improved excavator which can be readily applied to a well known type of tractor. f

Another object of our invention is to provide an improved, simple and eiiicient dlgging attachment for tractors wherein the digging arrangement and the tractor are driven from a common source of power.

`Another object is to provide an lmproved driving means for an excavator wherein the speed of the 'working parts may be varled independently of the speed of the vehicle carrying the excavator.

A further object of the invention is to provide an excavator having a conveyor mechanism driven by the same power unit which drives the working member and the vehicle propelling means.

Other objects and advantages of this 1nvention will be apparent from the following description taken in connection with the accompanying drawings wherein:

Fig. 1 is a side elevation of a tractor hav- 30 ing one of the endless tracks removed to more clearly show the digging attachment.

Fig. 2 is a topl plan view of a tractor equipped with my dig ing attachment.

Fig. 3 is a section ta en on line 3-3 of 35 Fig. 1 showing the' dirt loading device.

Fig. 4 is a front view of a tractor provided with my digging attachment showing part of the digging devices broken away to more clearly illustrate the invention.

Fig. 5 is a side elevation of the digging attachment frame and a portion of the trac-1 tor showing the frame in two positions.

Fig. 6 is a side elevation of the digging attachment frame showing the driving mechanism for the digging apparatus.

Fig. 7 is an enlarged side elevation showing the digging buckets and associated parts. Fig. 8 is a side elevation of the conveyor drive, and

head extends downwardly as at 31v and at Fig. 9 is a front face view ofthe conveyor support. A

Referring now to the drawings we have indicated a tractor generally at 10 as having an endless track mechanism 11 of usual form 55 which works over gear wheels 11 driven b an engine 12, from a shaft 13 (see Fig. 2g through the usual gearing contained in a housing 14. The housing 14 of the tractor includes hubs 15 which extend outwardly from each side thereof. Y n

These hubs support the gear wheels 11 and a frame 16. The frame 16 comprises side bars17 joined across the front of the tractor by a front member shown as a channel 18 to which spaced downwardly extending brackets 19 Iare secured.

Thesegbrackets 19 includ/e bearings for a bull wheel or roller 20 which may be of a single length extending transversely of the tractor the full width of the endless tracks 11, or may comprise a plurality of short roll'- ers.

The side brackets also form a support for a scraper plate 21, the function of which will be more fully described hereinafter. The plate 21 is secured to the side -brackets 19by means of bolts 21a and countersunk screws 21b and is provided with slots 21c for allowing of a vertical adjustment of the same (see Fi 3). A

supporting frame for our improved digl ging mechanism is shown at 22. Each side of the fra-me 22 consists of diverging arms 24 and 25 which are joined together adjacent their juncture by a plate 26. The plates 26l are supported on the side bars 17 on shafts 23. The members 24 extend forwardly to a point approximately over the /bull wheel 20 and are thereconnected by a transverse Vbar 27 (see Fig. 2). The construction is such that the frame may be swung about the axis of the shafts 23.

The lower arms 25 are shorter than the arms 24 and are each connected tothe stem 30 ofla T-shaped member. The head of this member has an upwardly directed part 29. whichis secured to the member 24 by rivets or other means 29. The other part of the the juncture of each stem 30 with the parts 29 and 31 we provide a slot 32 in whlch a bearing 32a is mounted (see Fig. 7). The bearings 32a are each resiliently engaged by a spring 32b which in turn engages a plate 32 which ma"1 be advanced along the slot 32 by means of ascrew 32d to support a shaft 33 on which sprockets 34 are mounted.

The lower ends of the parts 31 are slotted as at 35 to slidably receive a bearing 35a in which a shaft 35b is mounted. The bearing 35'* may be shifted in the slot 35 h v means of an adjusting device similar to that described in connection with the bearing 32a. The shaft 35h has three pairs of spaced pulleys 35c thereon.

Mounted in slots in the downwardly extending parts 31 are 'other bearings 38 which support shafts 39. These shafts 39 have rollers 40 thereon. The bearings 32a and 35. and 38 may al1 be adjustable and resiliently mounted as previously described.

The endless digging mechanism illustrated includes three sets of s aced chains having digging elements 41 t ereon. The chains are arranged so that they pass over the sprockets 34 and over the pulleys 35. The particular manner in which the diggin elements 41 are mounted on the chains 'orms no part of the .present' invention. The chains are engaged by the resiliently mounted rollers 40. Although we show three sets of digging elements will be understood that the number employed may vary without departing from the features of our invention.

It will lbe noticed by referring to Fig. 4 that the parts 29 of the supportin member extend outwardly and downward y on the outside of the digging elements 41, while the downwardly extending parts 31 are bent toward each other just below the shaft 33 so that their lower ends are disposed within the digging mechanism. This arrangement eliminates interference when digging a tench.

For driving the shaft 33 and the bucket drive sprockets 34, we provide` a sprocket 42 on the shaft 33. This sprocket 42 is adapted to be driven by a chain 43 from a sprocket 44 secured on a shaft l)f5/Which is arranged to be rotated by a wormiwheel46 thereon. The worm wheel 46 is shown as driven by a worm 47 secured to a shaft 48, which is adapted to be driven through the medium of a universal joint 49 by a shaft 50 of a change speed transmission 51.

The transmission 51 may be of any standard type of heavy duty type which includes a neutral or idle position and is shown as operated by a hand lever 52. The transmission 51 is shown as driven by a shaft 53 which has a worm wheel 54 secured thereon. The worm wheel 54 is driven by a worm 55 secured to a shaft 56. The shaft 56 is coaxial with the shafts 23 and is driven by a worm wheel 57 which is in turn 'driven b a worm58 secured to the engine drive sha't 13 (see Fi 2).

The sha; 48 is shown as supported in a bearing 59 on one of the frame side bars 24 while the shaft 53is supported in a bearing 60 of the pivot place 26 and the transmission is shown as supported by one of the side bars 24.

As shown in Fig. 5 the frame 22 is movable vertically about the axis of the shafts 23 and to bring about this movement one side bar 25 is provided with a slot 60a. intermediate its length in which a bearing 60h is slidably mounted.

The bearing 60 is supported by screw threaded engagement with a threaded shaft 61 which is rotatably supported in a thrust bearing 62 on one of the stationary side bars 17. The shaft 61 has a worm wheel'63 secured thereon which engages a worm 64 secured on a shaft 65. The shaft 65 has a hand wheel 66 secured to its rear end for rotating the same. From the foregoing description it will be apparent that upon rotating the hand-wheel 66 thedigging mechanism will be raised and lowered and due to the worm gears the mechanism will be maintained in set position.

At the forward end of the tractor and just in the rear of the endless bucket mechanism a conveying mechanism 67 is provided. This mechanism is mounted'on .a frame 67, which is adapted to be moved transversely of the tractor in shoes 68.

The dumping end of the conveyor mechanism is shown as supported by a yoke 70 which is in turn supported by a cable 71 passing' over a pulley 72 which is supported `by an upwardly extending frame 73 shown as secured to each side of the tractor in any desired manner. This frame is removable and may be shifted to either side when the conveyor 67 is shifted to either side.

The conveyor 67 includes an endless belt 74 and the entire conveyor may be moved so that it delivers the material excavated to either side of the tractor.4

The conveyor belt 74 is mounted on rollers 75 and 76 and is adapted to be driven by either roller, depending on which side the excavated material is to be discharged. .As shown in the drawings the belt 7 4 is driven by the roller 75.

The rollers 75 and' 76 are mounted on shafts 75 and 76 (see Fig. 8) which are supported by the frame 67 and have sprockets 77 and-78 mounted thereon for driving the same. The sprockets 7 7 and 78 are adapted to be driven by a sprocket chain 7 9 which is in turn driven by a sprocket 80. To maintain the sprocket chain 79 in close contact with the sprocket 80 a pair of idling sprockets 81 and 82 are provided. These ysprockets are rotatably mounted on ypivoted arms 83. y Thepivoted'arms83 are each held under tension by attaching one end of a coil'V -.to the shaft 56 (see/Fig. 2).

To allow the conveylng mechanism 67 to be lshifted transversely .of the tractor we have shown theshoes 68 aspivotally mounted in brackets l92 which are secured to the `transverse member 18 of the frame 16. The

conveyor frame 67a is secured to the shoes 68 by providing a plurality of threaded apertures y93 in the frame 67a which are adapted to be engaged by threaded bolts 94 passing through the shoes 68.

When it is desired to shift the conveyor mechanism 67 it is only necessary to remove the bolts 94, shift the conveyor mechanism tothe desired position and again secure the frame 67a to the'shoes 68 with the bolts 94.

`From the foregoingv description itwill be "apparent that the tractor engine 12 in addition to driving the tractor is adapted to prov1de motivepower for operating the endless tracksll, the digging mechanism, and

the conveyor mechanism 67, and that the` speed of the diggihg mechanism may be varied independent of the speed of the` tractor.

. When it is desired to operate our device for digging a shallow trench or for removing dirt and loading thesame on a vehicle for transportation, the engine 12 of the tractor is started and the transmission of vthe tractor is put in gearto cause it to inove forwardly, and at the same time the transmission 51 of the digging mechanism is putin gear to cause the digging mechanism to operate. The reversing transmission 89 is also arranged to drive the conveyor belt 74 in the desired direction.4

The character ofthe material being exca-4 vated or moved will determin the relative 'speed/ of the digging mechanis 411and the track 11.- If a hard substance is being exv cavated the digginormechanism ywill be ut high gear and the endless track ldriving mechanism jin low gear. For softer substances the endlessftrack driving mechanism may be put in highv gear while the digging devicemay be slowed down.

the buckets 40 of thediggingmecha'- nism remove thematerial they carry it upwardl'y and overthe drive sprocket 36 and discharge the material onto the conveyor mechanlsm 67 which conveys the same out-- ward and upward toits eXtreme end, where it is discharged so that it may fall onto'the `body of a truck which may move beside the digging tractor, or the material may be otherwise disposed of.

If for any reason loosev material gathers just in the rear of the lower end of the digging mechanism it will be carried along by the scraper plate 21 and the digging buckets will lgather it up and carry it until discharged on the conveyor 67.

If when excavating, the digging buckets run against a relatively immovable object such as large rock, the yieldable bearings 32a and 38 allow for a. rearward movement of the endless digging mechanism 41, while the bearing 35a allows an upward movement of the same. These movements allow the digging buckets to pass by` or avoid the interfering object, which may be removed after the tractor has been backed up out of edly mounted on said rear axle housing, a-

second frame pivotally mounted on said rst frame, means engaging said first frame to move the second frame, said second mentioned frame including an end member, adjustable and resiliently mounted spaced bearings in said end member, a pair of shafts on'said bearings, an endless bucket digging mechanism supported on said shafts,r means to drive one of said shafts, said means including a change speed transmission, and means to drivey said change speed' mechanism from said engine drive shaft, a vertically adjusted scraper plate mounted on said first mentioned framelin close proximity to said digging mechanism whereby loose dirt in vthe rear ofvsaid digging mechanism will be moved into the path of the descending portion of said `dlgglng mechamsm.

.shaft, arear axle housing, a frame ixedly mounted on said rear axle housing, a roller for .supporting the `front of the frame, a

vertically adjustable scraper plate mounted on said frame in front of said roller, a pair of shafts` on said frame, a second frame ivotally mounted on said shafts, a screw jack mounted on said rst frame, a nutV on said screw, said nut being mounted on said second trame, said screw having a worm wheel thereon, aworm adapted to rotate said worm wheel, a rearwardly extending shaft on which said wormis arranged, said shaft having a hand wheel secured thereon, said second mentioned frame including an end member, adjustable and resilient-ly mounted spaced bearings on said end ineinber, a pair ot spaced shafts on said bearings, an endless bucket digging mechanism supported on said shafts, a sprocket on one of said shaft-s, a chain engaging said sprocket, a second sprocket, a shaft tor said second sprocket, a worm wheel on said last mentioned shaft. a worm engaging said worm wheel, a rearwardly extending shaft on which said last mentioned worm is supported. a. universal joint on said rearwardly ext-ending shaft, another shaft engaging said universal joint, a change speed transmission connected to said shaft, and means to drive said change speed mechanism from said engine drive shaft, and a belt conveyor mechanism for receiving dirt from said digging mechanism.

3. In a digging mechanism including a frame, a pair of spaced upper and a pair of spaced lower bearings on said frame, said bearings being resiliently mounted in said .frame, said upper bearings being movable substantially horizontal and said lower bearings being movable substantially vertical, a. shaft supported by said lower bearings and another shaft supported by said upper bearings, and any endless digging mechanism supported by said shaftse 4r. In a digging `mechanism, means for elevating dirt, said means including a frame,

a pair ot spaced upper and a pair of spaced lower bearings on said frame, said bearings being resiliently mounted in said frame, said upper bearings being movable substan-z tially horizontal and said lower bearings being movable substantially vertical, a shaft supported by said lower bearings and another shaft supported by said upper bearings, a plurality ofv guide wheels on said lower shaft and a pluralityT of sprocket wheels on said upper shaft, the diameter of' said sprocket wheels being greater than the diameter ofthe guide wheels, an endless digging mechanism arranged over said sprockets and said guide wheels, said endless digging mechanism being adapted to be driven by said sprockets and means to drive said upper shaft.

5. In a digging mechanism including a frame, a pair of spaced upper and a pair of spaced lower bearings on said trame, said bearings being resiliently mounted in said frame, a shaft supported by said lower bearings and another shaft supported by said upper bearings, a pluralityy ot guide wheels on said lower shaft and a plurality of Lem-,587 Y sprocket wheels on said upper shaft, an endless digging mechanism arranged over said sprockets and said guide wheels, said endless digging mechanism being adapted to be driven by said sprockets and means to drive said upper shaft, a plurality of other guide wheels, said other guido wheels being adapted to engage the back of said digging mechanism and being positioned intermediate said uppersprockets and said lower guide wheels, a shaft for supporting said other guide wheels, and bearings for supporting said shaft, said bearings being resiliently mounted on said frame.

6. In a device of the class described, an endless 4tread tractor, a frame rigidly sefcured to said tractor and extending beyond the front ot said tractor, a bull wheel adapted to support the front end of said frame, another frame. pivotally connected adjacent the rear thereof to said first frame, means at the front of said pivoted frame for supporting an endless digging mechanism, and means on said first frame coacting with means on said pivoted frame for raising or lowering said pivoted frame.

7. In a device of the class described, an endless tread tractor, a frame rigidly secured to said tractor and extending beyond the front of said tractor, a bull wheel adapted to support the front end of said frame, another frame pivotally connected adjacent the rear thereof to said first frame, means at the front of said pivoted frame for sup,- porting an endless digging mechanism, means on said pivoted frame coacting with means on said tractor for driving said digging mechanism, said means on said pivoted rame including a change-speed transmission, and means on said first frame coacting with means on said pivoted frame for raising or lowering said pivoted frame.

In testimony whereof, we hereunto aliix our signatures.

RUDOLPH M. BOWMAN. BRUCE L. BOWMAN. 

